Updated display of player hand

display_game_state now shows a focused view of the current player's hand
with running total. Also swapped white versions of unicode suit
characters to black versions, improves legibility in IDLE at least.
![blackjack3](https://cloud.githubusercontent.com/assets/8142499/3564718/5d7f48f0-0a95-11e4-83ec-ce10d4695e48.png)